Update
A very interesting article at Ars Technica tells us why file systems matter. And it tells us a lot about Macs too !
From BFS to ZFS: past, present, and future of file systems
ZFS was the new file system that was rummored to be behind Leopard's Time Machine. ZFS has been developped by SUN Microsystem for their Solaris operating system.
Quote from the ZFS Open Solaris Page:
ZFS is a new kind of filesystem that provides simple administration, transactional semantics, end-to-end data integrity, and immense scalability. ZFS is not an incremental improvement to existing technology; it is a fundamentally new approach to data management. We've blown away 20 years of obsolete assumptions, eliminated complexity at the source, and created a storage system that's actually a pleasure to use.
ZFS presents a pooled storage model that completely eliminates the concept of volumes and the associated problems of partitions, provisioning, wasted bandwidth and stranded storage. Thousands of filesystems can draw from a common storage pool, each one consuming only as much space as it actually needs. The combined I/O bandwidth of all devices in the pool is available to all filesystems at all times.
Key word here: data integrity... For flawless backups etc...
Well, to tell you the truth, the above quote was from the ZFS Open Solaris Page via the ZFS on OS X page on MacForge, the provider of many a Free Software project for the Mac.
Which also means that YES! ZFS is available for the Mac !!!
To know more about it, go to Welcome to ZFS on OS X.